Implementation Of A Kind Of Block Cipher Based On Petri Net

In this thesis, the implementation of the block cipher based on un-bounded Petri net with unique reachable vectors, one of which is corresponded with one of reachable markings, is studied, k, the block's extent of the cipher, is variable and 2k permutations are produced by the running of Petri net.The concept of integer transformation system is presented to simulating the running of Petri net. Let ITS = (a, T) be an integer transformation system, a, a positive integer, is called initial integer. T = {t1, t2,..., tn } = { | j = 1,2, ... , n } is called transformation set. If cj | a, tj can be fired and the successive integer will be generated by a' = aej/cj.For a Petri net ∑ = (S, T'; F, M), |S| = m, |T'| = n, a list of prime numbers As = {p1,p2, ... ,pm } which are called assignment are assigned to place set. t'j T', let cj = then the integer transformation system corresponding to E and As of place set is generated.There is a monogamy between reachable markings of un-bounded integer transformation system with unique reachable integer and its reachable vectors. The partial reachable integer set is generated for 2k permutations by different extent of block and used for encryption and decryption. According to width-first-searching, the generation of partial reachable integer set is sorted by the sequence in diagonal order of reachable vectors, then sorted by reachable integers' value, 2k permutations is produced.In thesis, a multi-encryption scheme, that variable permutations is produced by clipping and sorting suitable for variable block's extent by generating a reachable integer set to sufficing the biggest block, is presented.In addition, four schemes are presented to suiting universal software and hardware implementation. They are throwing off redundant bits of block, built-up all bits of block, multi-BYTE parallel shifting and serial shifting.